Web feeding apparatus

ABSTRACT

Web feeding apparatus including a web diverting device which is controllable to cause a free leading end of a web to take a selected one of two alternative paths. The web diverting device comprises a pair of facing surfaces which diverge from each other in the web feeding direction whereby each defines a respective one of the two alternative paths. Air feed devices are arranged to direct a flow of air over either one of said surfaces as selected in the direction of web feed, to draw the web to that surface.

United States Patent [191 Jardine Oct. 29, 1974 WEB FEEDING APPARATUS3,236,517 2/1966 Lyman ..271/19sx 75 Inventor: Robert W.Jardine,Stockport, 533;"

England I [73] Assignee: Reed International Limited, PrimaryExaminer-Willie G. Abercrombie London, England Filed: May 15, 1973 Appl.No.: 360,494

U.S. Cl 83/98, 83/102, 83/402, 226/97, 271/195 Int. Cl B26d 7/06, B65h17/32 Field of Search 83/98, 99, 102, 402; 226/97; 271/195 ReferencesCited UNITED STATES PATENTS 6/1964 Lyman 271/195 X 8/ 1964 Obenshain226/97 X CONTROL BOX AIR SUPPLY l l l I l 1 I 54 1 Attorney, Agent, orFirm-Elliott l. Pollock [57] ABSTRACT Web feeding apparatus including aweb diverting device which is controllable to cause a free leading endof a web to take a selected one of two alternative paths. The webdiverting device comprises a pair of facing surfaces which diverge fromeach other in the web feeding direction whereby each defines arespective one of the two alternative paths. Air feed devices arearranged to direct a flow of air over either one of said surfaces asselected in the direction of web feed, to draw the web to that surface.

4 Claims, 1 Drawing Figure WEB FEEDING APPARATUS This invention relatesto web feeding apparatus and has particular, but not exclusive,application to the feeding of paper webs to winding devices for windingthe webs into rolls.

One intended application of the invention is in winding machines forwinding wallpaper into standard length rolls for supply to the retailtrade. The wallpaper is usually fed as a continuous web to such machinesfrom a large reel and in its feed is severed to form the tail end of oneroll and the'leading free end of the next roll. Where the windingmachine has a single winding head it is necessary to provide a hold"system for the leading end of the next roll until the winding head isready to receive it following completion and removal of the precedingroll. This results in a build up of web in the hold" system which has tobe eliminated by high acceleration of the winding head at the start ofthe next winding operation. The high acceleration can lead to damage orbreaking of heavy embossed wallpaper and webs of low tensile strength.

As an alternative to the use of a single winding head and a hold system,two winding heads can be used so that at the end of a winding operationon one head the leading free end for the nextroll is diverted to theother winding headto provide in effect an uninterrupted windingoperation. in attempting to design a machine to operate in this wayconsiderable difficulties have been encountered in diverting the leadingend of the web for the next roll after the severing operation. Attemptshave been made to use mechanical fingers and suction rollers forchanging the direction of the web. Problems arise in the use of fingersbecause there is no gap between the severed ends of the web throughwhich fingers can be inserted and it is undesirable to create a gap byremoving a transverse strip from the web. The use of suction rollersleads to difficulties in removing the web from the'rollers after it hasbeen diverted and problems arise from windage created by the suctionrollers having to rotate at high speeds.

The object of this invention is to provide web feeding apparatusincluding a web diverting device which does not suffer from theaforesaid disadvantages.

According to this invention there is provided web feeding apparatusincluding a web diverting device which is controllable to cause a freeleading end of a web to take a selected one of two alternative paths,the web diverting device comprising a pair of facing surfaces whichdiverge from each other in the web feeding direction whereby eachdefines a respective one of the two alternative paths, and means fordirecting a flow of air over either one of said surfaces as selectedwhereby the free leading end of a web passing between the facingsurfaces is drawn to the one over which the flow of air is directed.

In accordance with the so-called Coanda effect the air flow will tend tofollow the surface over which it is directed and in accordance withwell-known fluid flow boundary layer theory (Bernouille Law) the webwill be drawn towards the surface over which the air flow is directedbecause of the drop in pressure between the web and said surface causedby the air flow.

The flow of air provides lubrication between the surfaces and the weband constrains the web to follow the contour-of the plate surfaces.

ln application of the invention to a winding machine having two windingheads and web severing means, the web severing means may operate bypassing through the diverting device or the latter may be positionedbetween severing means and the winding heads.

One embodiment of the invention as applied to a winding machine forwallpaper rolls will now be described by way of example with referenceto the accompanying diagrammatic drawing.

The winding machine has two winding heads 1 and 2 of well knownconstruction. The web 40 is fed into the machine overa guide plate 3,then over guide rollers 4 and 5, through nip rollers 6 and 7 and thencethrough the diverting device 9 to one or other of the winding heads 1and 2 as will be described.

The diverting device 9 comprises two facing plates 10 and 11 whichextend parallel to each other for a length and are then curved todiverge from each other in the direction of web feed. Thus the plate 10defines the web feed path to the winding head 1 and the plate 11 definesthe web feed path to the winding head 2. Associated with the plates 10and 11 are respective air feed devices 12 and 13 which are located ingaps in the parallel portions of the plates 10 and 11 and have orifices14 through which air is fed, the orifices being directed so that the airfrom device 12 flows downwardly over the surface of plate 10 and the airfrom device 13 flows downwardly over the surface of plate 11 as shown bythe arrows.

. A plate 15 of inverted V form is disposed below the plates 10 and 11.One arm 16 of the V converges towards the plate 10 to define with theplate 10 a narrowing guide throat 17 leading to the winding head 1. Theother arm 18 of the V similarly defines with the plate 11 a narrowingguide throat 19 leading to the winding head 2.

Severing means in the form of blades 20 and 21 are disposed to passthrough transverse gaps in the plates 10 and 11 respectively, at theposition where the plates 10 and 11 commence to diverge, to sever theweb 40 transversely. The blades 20 and 21 are pneumatically operatedthrough double acting air cylinders 22 and 23 and in their forwardprojecting position after severing the web, as shown for the blade 20,form a gate closing the adjacent guide throat.

Control means shown diagrammatically by control box 24 in the drawingare arranged to control the air flow from a pressurized supply to theair feed devices 12 and 13 and the air cylinders 22 and 23. Thus thecontrol means comprises a valve arrangement made up of conventionalvalves and whose inter-relationship will be readily understood from thefollowing description of the operation of the winding machine.

in the situation shown in the drawing the winding of a roll 41 inwinding head 1 is just being completed, the severing blade 20 has justbeen operated to sever the web 40 to produce free leading web end 42 andto close the throat 17 so that leading web end 42 can not enter thethroat 17. Also air is flowing over the surface of plate 11 so that theweb 40 is drawn towards plate 11 and is thus directed through throat 19to winding head 2. Once the leading web end 42 has been taken up bywinding head 2 so that it is held thereby a control signal from windinghead 2 via line 25 to control box 24 causes, after a predetermined timedelay controlled by a timing device in box 24, the air supply to aircylinder 22 via line 27 to be switched to the other side of the pistontocause it and the blade 20 to be retracted.

Upon completion of the winding of the roll in the winding head 2 to apredetermined diameter a signal is passed to the control box 24 fromwinding head 2 via line 29, to cause the air supply to be connected toair feed device 12 via line 28 so that there is a flow of air over thesurface of plate and to be connected via line 30 to air cylinder 23 tocause operation of severing blade 21. This results in severing of theweb 40, closure of throat 19 and drawing of the free leading end of theweb thus produced towards plate 10 so that it is guided through throat17 to winding head 1. Thereafter, in a manner corresponding to thatpreviously described, a signal is passed from winding head 1 via line 32to the control box to cause the air supply to air feed device 12 and aircylinder 23 to be cut off. Severing blade 21 is then retracted by an airsupply on the other side of the piston. This is initiated through atiming device as described for air cylinder 22.

Also in a manner corresponding to that previously described, completionof the winding of the roll in winding head 1 causes a signal to bepassed from winding head 1 to control box 24 via line 34 causing air tobe fed to air feed device 13 and operation of severing blade 21 by aircylinder 21 resulting once again in the situation shown in the drawing.

The diverting device 9 has been found to work satisfactorily using anair pressure supply at about 10 to pounds per square inch, the rate ofair flow over each plate 10, 11 being about 1 cubic foot per minute perinch across the plate surface. Thus if the plates 10 and 11 are 24inches wide and the air feed devices 12 and 13 extend across their fullwidth, each air device 12, 13 would produce an air flow of 24 cubic feetper minute. To achieve this the orifice 14 which would extend as a stripacross the width of its associated plate 10, 11, is of the order of .002inches wide.

I claim:

1. Web feeding apparatus including a web diverting device which iscontrollable to cause a free leading end of a web to take a selected oneof two alternative paths, the web diverting device comprising a pair offacing surfaces which diverge from each other in the web feedingdirection whereby each defines a respective one of the two alternativepaths, the facing surfaces of the diverting device extendingsubstantially parallel to each other for a length before they commenceto diverge, and means for directing a flow of air over either one ofsaid surfaces as selected in the direction of web feed, whereby the freeleading end of a web passing between the facing surfaces is drawn to theone of the surfaces over which the flow of air is directed, the meansfor directing the flow of air over the facing surfaces comprising airfeed devices respectively disposed in each of said facing surfaces partway along their substantially parallel portions, and web severing meanspositioned to sever the web substantially at the commencement of thedivergence of said facing surfaces.

2. Web feeding apparatus according to claim 1, wherein the web severingmeans comprise a pair of web severing blades, each arranged to be movedfrom an inoperative position behind a respective one of the facingsurfaces to a position in which it projects through the facing surfaceto sever the web.

3. Web feeding apparatus according to claim 2, wherein the divergingportions of said facing surfaces each define together with a furthersurface a web guiding throat and each of said blades in its projectingposition closes the adjacent throat.

4. Web feeding apparatus according to claim 2, wherein control means areprovided for controlling the air feed devices and the web severingblades so that upon movement of one blade so that it projects throughone of said facing surfaces to sever the web, the air feed deviceassociated with the other surface is caused to supply a flow of air oversaid other surface.

1. Web feeding apparatus including a web diverting device which iscontrollable to cause a free leading end of a web to take a selected oneof two alternative paths, the web diverting device comprising a pair offacing surfaces which diverge from each other in the web feedingdirection whereby each defines a respective one of the two alternativepaths, the facing surfaces of the diverting device extendingsubstantially parallel to each other for a length before they commenceto diverge, and means for directing a flow of air over either one ofsaid surfaces as selected in the direction of web feed, whereby the freeleading end of a web passing between the facing surfaces is drawn to theone of the surfaces over which the flow of air is directed, the meansfor directing the flow of air over the facing surfaces comprising airfeed devices respectively disposed in each of said facing surfaces partway along their substantially parallel portions, and web severing meanspositioned to sever the web substantially at the commencement of thedivergence of said facing surfaces.
 2. Web feeding apparatus accordingto claim 1, wherein the web severing means comprise a pair of websevering blades, each arranged to be moved from an inoperative positionbehind a respective one of the facing surfaces to a position in which itprojects through the facing surface to sever the web.
 3. Web feedingapparatus according to claim 2, wherein the diverging portions of saidfacing surfaces each define together with a further surface a webguiding throat and each of said blades in its projecting position closesthe adjacent throat.
 4. Web feeding apparatus according to claim 2,wherein control means are provided for controlling the air feed devicesand the web severing blades so that upon movement of one blade so thatit projects through one of said facing surfaces to sever the web, theair feed device associated with the other surface is caused to supply aflow of air over said other surface.